The road to beating leukemia, lymphoma or other blood cancers often takes patients through a stem cell transplant. But in curing the cancer, transplants can cause a host of other issues, one of which is a lung disorder called bronchiolitis obliterans syndrome, or BOS.
BOS blocks the flow of air to the small airways in the lungs and is very difficult to treat once it becomes advanced. About 10% of patients who survive a stem cell transplant develop BOS.
Unfortunately, BOS is also difficult to diagnose, so by the time it’s identified doctors are not able to reverse it. The goal becomes to stop it from getting worse. Only 1 in 5 patients will survive five years after a BOS diagnosis.
New research offers hope
But what if you can detect signs of BOS early? A team of researchers at the University of Michigan Comprehensive Cancer Center have found a promising new approach to diagnosing BOS earlier. They believe this would allow for treatment to slow the disease, dramatically improving survival.
The technique is called parametric response mapping. It was developed by a team of radiology and transplant specialists at the University of Michigan, including Ella Kazerooni, M.D., Gregory Yanik, M.D., Brian Ross, Ph.D., andCraig Galban, Ph.D.
The approach involves taking CT scans of the lungs when a patient has taken a full breath and when the patient has fully exhaled. These images are then warped to align individual voxels between the two scans. By looking at it this way, the researchers found they could determine what type of lung issue is present and how severe it is.
Diagnosing BOS is complicated because patients frequently develop lung infections following transplant, which makes it difficult to accurately assess the problem. Using the parametric response mapping, the team found that increased levels of functional small airway disease could be detected, whether the patient had a lung infection or not.
The research is published in the journal Biology of Blood and Marrow Transplantation and still needs further testing before it can be used widely. The University of Michigan has licensed the technology to Imbio, LLC, which has built cloud-based and PACS-based software platforms to provide results to clinics based on lung CT scans submitted for analysis.
Clinical trial will be next
The study looked back at data collected from 53 transplant patients with infection, BOS or BOS plus infection and compared them to 23 patients who did not undergo a transplant. Now, the U-M team is developing a clinical trial to test the approach along with potential early interventions.
“The ability for parametric response mapping to both quantify and spatially define the severity of lung airway disease in patients with BOS may serve as a major advance in the diagnosis and management of this disorder,” says lead study author Craig Galban, Ph.D., associate professor of radiology and biomedical engineering at U-M.